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Biomedical subjects

T Korhonen

Publications and source records attributed to T Korhonen.

At least 109 records · Page 6Linked to original sources
PubMed1982

Modification of the metabolic and hormonal response to physical exercise by beta-blocking agents.

Beta-blockade is known to induce muscle fatigue and tendency to hypoglycaemia during prolonged exercise. In addition, beta-blocking agents influence the secretion of many hormones, which regulate glucose. We have investigated the effects of a beta 1-selective (metoprolol) and a non-selective (propranolol) beta-blocking agent on muscle glycogenolysis, blood glucose and lactate levels, plasma levels of free fatty acids and on secretion of insulin, growth hormone, glucagon and cortisol during physical exercise in a double blind cross-over study in seven healthy male volunteers. They participated in three bicycle ergometer tests each lasting for 30 minutes under treatment of placebo (C), metoprolol (M) or propranolol (P). A biopsy was obtained from the vastus lateralis muscle before and immediately after the exercise for muscle glycogen assay. The glycogen concentration after exercise tended to be lower in C than in M or P experiment. The blood glucose level decreased during P and at 30 min there was a significant difference between P and C. The blood lactate was significantly lower before exercise during P than C or M. The increase of blood lactate during exercise, however, was not inhibited by P. Both beta-blocking agents counteracted the increase of FFA during exercise. There was a marked increase of growth hormone secretion during beta-blockade. The secretion of glucagon and cortisol were slightly increased by P and M, but the plasma insulin level was not affected by beta-blockade.

Adult↗
PubMed1981

Adhesion of Escherichia coli in urinary tract infection.

In individuals prone to urinary tract infections the intestine is colonized by E. Coli strains that possess a combination of properties determining virulence. Such an E. coli strain may colonize the vaginal and periurethral area and ascend the urinary tract. The ability to attach to the mucosal surface is thought to be essential for E. coli to colonize and to remain in the urinary tract. Most E. coli from patients with urinary tract infection show one or both of two adherence properties. One may depend on the recognition by type 1 fimbriae of mannose-containing residues in the urinary slime. It is measured as mannose-sensitive haemagglutination and is found on most E. coli strains. The second adherence property is detected as attachment to human urinary tract epithelial cells and as mannose-resistant agglutination of human erythrocytes. This may depend on the recognition of globo-series glycolipids in the epithelial cell surface. Possession of this adherence factor is strongly related to virulence. Most strains from patients with acute pyelonephritis and cystitis have this property but it is rare in strains from patients with asymptomatic bacteriuria and strains from normal faeces. Local antibodies may interfere with bacterial attachment, thus possibly preventing the colonization that precedes urinary tract infection or modifying an established infection. Vaginal antibodies are known to coat E. coli from the stools. Antibodies in the urine of patients with acute pyelonephritis inhibit attachment of the infecting strain to uroepithelial cells. Antibodies directed against several bacterial surface structures, for example O antigen and fimbriae, are likely to inhibit attachment by steric hindrance or agglutination. The role of antibodies in adhesion-mediating structure such as fimbriae in susceptibility to and the outcome of human urinary tract infection remains to be investigated.

Adhesiveness↗
PubMed1981

Improved diabetic control and hypocholesterolaemic effect induced by long-term dietary supplementation with guar gum in type 2 (insulin-independent) diabetes.

The effects of dietary supplementation with granulated guar gum (21 g/day in three divided doses at the main meals), were compared with placebo response during three months in a double-blind, cross-over trial in 11 Type 2 (insulin-independent) diabetes. The nine patients who complete the study (two dropped out because of side-effects) showed a significant reduction in both basal and post-prandial hyperglycaemia as well as of urinary excretion of glucose during guar gum supplementation. No change in mean bodyweight was observed during the study. Mean fasting and post-prandial plasma insulin levels were similar during both study periods, but the two subjects who received no oral hypoglycaemic agents had lower insulin levels during the guar gum period. Mean serum total- and LDL-cholesterol concentrations were significantly lower during the guar gum period, whereas the HDL-cholesterol level remained unchanged. Long-term administration of guar gum induced a sustained improvement in diabetic control in Type 2 diabetes.

Adult↗
PubMed1980

Effect of discontinuation of biguanide therapy on metabolic control in maturity-onset diabetics.

Control of blood-glucose levels was monitored for 12 wk after withdrawal of biguanides in a group of 118 diabetic patients treated with biguanides (alone or in combination with sulphonylurea) from a population of 39,200. The mean fasting blood-glucose level rose during the first 2 wk from 9.2 +/- 0.3 to 11.3 +/- 0.4 mmol/l (p less than 0.001) and the mean urinary-glucose excretion from 11.7 +/- 3.7 g/24 h to 36.5 +/- 5.5 g/24 h (p less than 0.001), respectively. The change in blood-glucose concentration did not depend on age, sex, bodyweight, or duration of diabetes or biguanide treatment. The mean increase in blood-glucose was similar (2.1-3.1 mmol/l) in subjects with their initial blood-glucose level less than or equal to 6.0 mmol/l, 6.1-11.0 mmol/l, and greater than or equal to 11.1 mmol/l. There were no changes in blood-lipids or bodyweight during the observation period. Biguanides reduced blood-glucose levels in most patients with maturity-onset diabetes. The hypoglycaemic effect was similar in subjects with normal and increased bodyweight and did not depend on the duration or severity of diabetes.

Aged↗
PubMed1979

Biguanide-induced lactic acidosis in Finland.

Twenty-four patients with biguanide-induced lactic acidosis were reported to the Adverse Drug Reaction Register of the Finnish National Board of Health from 1974-1977. Of them, 23 had been treated with phenformin and one with metformin. The mean age of the patients was 71 years, and all but one were more than 65 years of age. The mortality rate was 63%. One patient had cirrhosis of the liver and one was already known tohave had impaired renal function. Fourteen of the patients had a normal serum creatinine concentration either before or after the development of lactic acidosis. Thus, in most patients it had not been possible to prevent development of lactic acidosis by observing the contraindications to biguanide therapy. Most patients had some form of co-existing cardiovascular disease. Tetracycline therapy was a probable precipitating factor in three cases. Based on the statistics of biguanide consumption in Finland, the annual incidence of biguanide-induced lactic acidosis in 1976 and 1977 was between 1/2000 and 1/3000 and that of fatal lactic acidosis was 1/4000.

Acidosis↗
PubMedDate not supplied

Neurological development of 5-year-old children receiving a low-saturated fat, low-cholesterol diet since infancy: A randomized controlled trial.

CONTEXT: Early childhood introduction of nutritional habits aimed at atherosclerosis prevention is compatible with normal growth, but its effect on neurological development is unknown. OBJECTIVE: To analyze how parental counseling aimed at keeping children's diets low in saturated fat and cholesterol influences neurodevelopment during the first 5 years of life. DESIGN: Randomized controlled trial conducted between February 1990 and November 1996. SETTING: Outpatient clinic of a university department in Turku, Finland. PARTICIPANTS: A total of 1062 seven-month-old infants and their parents, recruited at well-baby clinics between 1990 and 1992. At age 5 years, 496 children still living in the city of Turku were available to participate in neurodevelopmental testing. INTERVENTION: Participants were randomly assigned to receive individualized counseling aimed at limiting the child's fat intake to 30% to 35% of daily energy, with a saturated:monounsaturated:polyunsaturated fatty acid ratio of 1:1:1 and a cholesterol intake of less than 200 mg/d (n = 540) or usual health education (control group, n = 522). MAIN OUTCOME MEASURES: Nutrient intake, serum lipid concentrations, and neurological development at 5 years, among children in the intervention vs control groups. RESULTS: Absolute and relative intakes of fat, saturated fatty acids, and cholesterol among children in the intervention group were markedly less than the respective values of control children. Mean (SD) percentages of daily energy at age 5 years for the intervention vs control groups were as follows: for total fat, 30.6% (4.5%) vs 33.4% (4.4%) (P<. 001); and for saturated fat, 11.7% (2.3%) vs 14.5% (2.4%) (P<.001). Mean intakes of cholesterol were 164.2 mg (60.1 mg) and 192.5 mg (71. 9 mg) (P<.001) for the intervention and control groups, respectively. Serum cholesterol concentrations were continuously 3% to 5% lower in children in the intervention group than in children in the control group. At age 5 years, mean (SD) serum cholesterol concentration of the intervention group was 4.27 (0.63) mmol/L (165 [24] mg/dL) and of the control group, 4.41 (0.74) mmol/L (170 [29] mg/dL) (P =.04). Neurological development of children in the intervention group was at least as good as that of children in the control group. Relative risks for children in the intervention group to fail tests of speech and language skills, gross motor functioning plus perception, and visual motor skills were 0.95 (90% confidence interval [CI], 0.60-1.49), 0.95 (90% CI, 0.58-1.55), and 0.65 (90% CI, 0.39-1.08), respectively (P =.85,.86, and.16, respectively, vs control children). CONCLUSION: Our data indicate that repeated child-targeted dietary counseling of parents during the first 5 years of a child's life lessens age-associated increases in children's serum cholesterol and is compatible with normal neurological development. JAMA. 2000;284:993-1000

Child Development↗
PubMedDate not supplied

Evaluation of a national Quit and Win contest: determinants for successful quitting.

BACKGROUND: Within the CINDI framework, a European "Quit and Win" contest was organized in 1994. In Finland the number of participants was 5,879 (0.6% of smokers). In the CINDI demonstration area, North Karelia (NK), the participants numbered 618 (2.0% of smokers). This study compared abstinence maintenance among the participants in NK with the rates found elsewhere in Finland and analyzed determinants for successful quitting. METHODS: A follow-up study was conducted 12 months after the quit date with a sample of 2,114 participants. Response rates of 67-68% were achieved (n = 1,419). The abstinence was assessed at 1, 6, and 12 months. Two estimates are presented: (1) the proportion of abstainers among the respondents and (2) the proportion of abstainers among the sample, considering all nonrespondents smokers. The determinants for maintenance of smoking cessation were analyzed with logistic regression. RESULTS: Using the first estimate, the rates at 1/6/12 months were 75/36/28% in NK and 70/28/21% elsewhere (P < 0.01). Using the second estimate, the corresponding rates were 50/24/19% in NK and 46/19/14% elsewhere. The most significant determinants for successful quitting were sex, age, marital status, level of withdrawal symptoms, previous quitting attempts, and support received. CONCLUSIONS: The recruitment of smokers and the maintained cessation were more successful in the demonstration area. The difference between areas was explained by differences in the combined professional and lay support and by the sex and age distributions.

Adult↗
PubMedDate not supplied

Evidence of the origin of specific spontaneous head turns during intertrial intervals.

Direction and the frequency of spontaneous head movements during the ITIs following forward and backward paired trials were compared to an acquisition of a conditioned orienting (alpha) response directed to the side of the tone source. The head movements were analyzed from video recordings using classification of head turns to preferred and to nonpreferred directions. The results showed a significant increase in the alpha responses during the forward paired conditioning to the preferred direction and rapid extinction during the subsequent backward conditioning sessions. Spontaneous head movements during the ITIs increased to the same preferred direction as the conditioned alpha responses. The results of this experiment suggest that the response initially elicited by the CS can later appear as "spontaneous," instrumental behavior, the form and the nature of which is determined by the characteristics of the conditioned alpha response developing as a result of classical conditioning.

Animals↗